Both plates of a capacitor do not necessarily have to hold equal amounts of charge, as charge conservation applies to the entire system, including the battery and wires. If there is an imbalance in charge, it can lead to significant voltage differences across the capacitor. The discussion highlights that a battery does not simply absorb charge; it facilitates a flow of current, maintaining charge balance. Capacitors can exhibit stray capacitances that affect their potential, complicating the relationship between charge and voltage. Ultimately, while equal charges on capacitor plates are common, they are not a strict requirement for functionality.